Particle Theory
What does the particle theory say about all matter?
All matter is made up of tiny particles.
Name the three main states of matter.
Solid, liquid, gas.
What do we call a solid changing to a liquid?
Melting.
What is another word for “heat energy”?
Thermal energy.
What two states of matter are considered fluids?
Liquids and gases.
What happens to the particles when temperature increases?
They move faster.
Which state has a definite volume but no definite shape?
Liquid.
What process changes a liquid to a gas?
Evaporation or Boiling (Vaporization).
What happens to the thermal energy when water boils?
It increases.
Why are liquids called fluids?
Because they can flow and take the shape of their container.
How are the particles in a solid arranged compared to a gas?
Why can gases be compressed easily?
The particles are far apart.
What process changes a gas directly into a solid?
Deposition.
What is the process of heat transfer through solids called?
Conduction.
What does “viscosity” mean?
A fluid’s resistance to flow.
What holds particles together in a solid?
Strong attractive forces.
What property makes a solid maintain its shape?
Strong particle attraction and fixed positions.
Is freezing an example of adding or removing heat energy?
Removing heat energy.
What happens to a fluid during convection?
Cold fluids rise and hot fluids sink creating a "convection" current.
How does heating a fluid affect its viscosity?
It usually decreases (flows faster).
What term describes the spaces between particles?
Intermolecular spaces.
What happens to the density of a substance as it changes from solid → liquid → gas?
It generally decreases.
What happens to particle spacing and movement during condensation?
Particles slow down and move closer together.
Explain what happens to the particles when energy is removed from a gas.
They slow down and move closer, forming a liquid or solid.
Why do gases flow more easily than liquids?
The particles in gases are farther apart and move faster.